When the mount is fully inserted, the leash is just long enough for the loop on the end of it to just fit over the end of the motor hook when I pull it down along the outside of the body tube. With it looped over the end of the hook, the leash slides up the hook and tightens against the body tube when the motor mount is pulled out, and it is just long enough to stop the mount when it reaches the end of the hook.

During installation, after I slip the loop over the end of the motor hook, I pull the mount down to tighten the leash against the side of the body tube. Then I put one wrap of 1/2-inch wide Mylar tape around the vent holes to cover them. This keeps the leash held against the body, so that it doesn't flap around after I push the mount back up into the body. But the main reason that I cover up the vent holes is because they are too large for the Micromaxx motor's tiny ejection charge. I poke a small hole in the Mylar tape over each vent hole to allow the ejection charge to vent.

I built the mount out of a combination of a BT-5 coupler and a length of BT-4, in order to make it long enough to reach the base of the nose cone when the mount is fully inserted. A combination of two couplers glued together could also be used. The mount has to be long enough to reach up past the vent holes, yet be light enough to keep the rocket from exceeding the maximum liftoff weight for the Micromaxx-II motor (around 18 - 20 grams).

I constructed the Micromaxx adapter so that I could install in and remove it easily, to allow me to switch between flying the model on 6 mm and 13 mm motors.

Mark \\.

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SAM # 0011